Automatic circuit-breaker.



No. 345655- YATENTED FEB. 26, i992? H. W. LEONARD.

AUTUMATIO CIRGUT BREAKBR. APPLIUATION MLB@ 13153.21. 1901.

a slnzsfrss1131.15*g)L n HH lll In ven tor PATENTE?) FEBl 26; 190?. EL W, L qft AUTOMC CIRCUIT BREAKBR.

APPLGATION FILED MAR. 2l, 1901.

3 SHEETS-SHBET 3.

HARRY VARD LEONARD, QF NEW YORK, N. Y.

AUTOMATIC CIRCUIT-BREAKER.

Specification of Letters Patent.

Patented Feb. 26, 1907.

Application tiled March 21, 1901.` Serial No. 52,128.

v To all whom it may concern:

Be it known that 1, HARRY WARD LEON- ARD, a citizen of the United States, residing in the borough of Manhattan, city of New York, State of New York, have invented a certain new and useful Improvement in Automatic Circuit-Breakers.of which the following is a description.

My invention relates to improvements in circuit-breakcrs and similar devices, andespecially to circuit-breakers of' the type in which one`or more switches or their equivalents are operated automatically whenever the circuit conditions Vary beyond certain limits.

In someiorms of the invention abnormal variations of amperes in the circuit affect the operation, the circuit being broken at one or more places whenever the number of ainperes exceeds or falls below the desired limit. In some forms of the invention the element of voltage is the factor which determines the automatic operation, the circuit being broken when the voltage of the current exceeds or falls below predetermined limits. In other forms oi' the invention one element may be controlled by the volts and another by the current for example, a device will be automatically actuatedwhen the current exceeds a predetermined limit and a device will also be automatically actuated whenever the volts fall below a certain predetermined limit. There are many combinations ol various possible limits both in respect to current and voltage which are useful in connection with the control of circuits supplying various kinds of electricaltranslating devices. Furthermore, in some instances a reversal oi' currentor reversal of electromotive force may determine the limit, causing the automatic action of a controlling device. 1n other instances the element lof time may determine the automatic operation. For example, a maximumampere device may operate when a predetermined increase in the amperes has continued for a certain predetermined length ofv time, or a minimum-voltage device may automatically act when the volts have' been. reduced to a certain amount for a certain length of time. Sometimes the temperature may determine the limit. For example,

" when the temperature at a certain point exceeds a certain amount a controlling device willbe automatically actuated. Sometimes 'an increase or diminution of pressure at a certain point may determine the limit. Sometimes the velocity of movement of some device may be the controlling element. Sometimes the movement oi' a device relative to another device may be the controlling elementaa for example, a pendulum whose support is moved beyond a certain limit,

. In order that the invention may be better understood, attention is directed to the accompanying drawings, forming part of this specification, and in whichl* igure 1 is a -iront elevation, partly in section, of an automatic switch for breaking the circuit when the current therein exceeds or falls below a definite limitf Fig. 1a is a section on line a; of VEig. 1 g Fig. 2 a view similar to Fig. 1, showing the employment of two switches, both of vi hich simultaneously open on an increase of current beyond the desired limit and one of which opens when the current ifalls below the desired limit; Fig. 3, a view similar to F ig. 2, showing the device in employment with a shunt-wound electric motor and wherein the circuit thereto will be broken when the voltage fails or in the event of an overload; Fig. 4, a diagram of a somewhat-similar arrangement, illustrating it in connection with a series motor and with a rio-voltage coil shunted directly across the line; Fig. 5,..a diagram illustrating the automatic circuit-breaker in connection with the charging of a storage battery and providing for an automatic opening oi the circuit when the electromotive force falls below a predetermined minimum and when it exceeds a predetermined maximum; big. 6, a corresponding view show ing -the invention applied to protect a translating device against an excessive increase in electromotive force or current; liig. 7 a corresponding view show ing a modified arrangement for accomplishing the same purpose; big. 8, a corresponding view illustrating the circuit-breaker applied in connection with the charging of a storage battery and providing for the automatic breaking of the circuit in the event of a reversal of current; liig. 9, a corresponding 'view of a modiicationfor' accomplishing the same purpose; big. 10, a corresponding view showinga no-voltage and overload circuitbreaker of moditiedform operating in-connection with a shunt-motor; lg. 11, a view similar to iiig. .6, showing the device in use in -IOO event of reversal of current.

connection with the charging of a storage battery and illustrating. a polarized relay for eflecting the automatic operation in the Fig. 12 is a diagram of a modification.

ln all of the above views corresponding parts are represented by the same vnumerals of reference.

ln Big. 1 a knife-blade switch 1 is adapted to close a circuit betw een contacts 2 2 and to be normally locked in its closed position by means of a latch 3, as described in patent granted to myself and Henry Price Ball for electric circuit-breakers, July 22, 1902, No. 705,102. The latch 3 is mounted on a rockshaftV 4, from which trip-arms 5 and 6 extend, as shown. The rock-shaft 4 is mounted in bearings on the base-plate, and a spring is coiled round the shaft with one end engaging one of said bearings and the other end.

engaging the back of latch 3 to throw it into the latching position. Cooperating with the trip-arm 5 is the core 7 of an overload-solenoid 8, which core carries a disk, as shown, and cooperating with the trip-arm is a lever 9, adapted to be engaged by the disk on core 10 of a minimum-load solenoid 1v1. As shown, the windings of the two selenoids are in series with each other and the switcl'i-contacts 2 2'. minimum-load solenoid is held up by the magnetizing force of the solenoid, which is opposed by gravity. The magnetic pull of the circliit-current can be varied within limits, as desired, by adjusting a non-magnetic screw 12 at the top ot the solenoid, by

which the position of the plunger can be varied relative to the solenoid. 1f' the current be gradually reduced, the magnetic pull supporting the plungerl against gravity will gradually become less, and finally at a detinite number of amperes the core 10 will fall by its weight and will strike the lever 0 with a blow, tripping thelatch' 3 and permitting the switch 1 to be opened by the usual ordinary operating-spring. The plunger 7 ot thel overload-solenoid is normally down, as shown, and in the event ot an overload the magnetic pull will elevate the plunger with an accelerated velocity, releasing the latch 3 and permitting the automatic opening ofthe switch. l

In Fig. 2 the construction is substantially the same, except that the core 7 o'l` the overload-solenoid Salso operates the trip 13 ot a switch 14, which normally closes a circuit between contacts 15 15. As shown, both coils and switches are in, series with each other. In the event ot an underload the core l0 will drop to trip the latch 3 and permit the switch 1 to open. In the event of an overload the core 7 will be elevated, tripping the latches 3.and 13 and permitting both or' the switches to open. 1n the event of an overload`` therei'ore, caused, for example, by a The core or plunger 10 oi' the' short c ircuit, the closing of the switch 1, succeeded h y the closing ol the switch 14, will it the short circuit still exists result in the operation of the solenoid S to release the switch 1 and again break the circuit. With this i'orm of device, therefore, as described in said patent of Leonard and Ball, the maximumcircuit breaker cannot be closed by the operator when the condition of the circuit is such that the closing ot the circuit causes a current exceeding the predetermined maximum.

In Fig. 3 is shown ay'double-pole circuitbreaker having two switches 1 and 14, as shown in Fig. 2, and wherein the coil 11 is shown in series with the switch 1, the iield 16 ot a shunt-motor, and the switch 14. The overload-coil 8 is in series with switches 1 and 14, with the armature 17 ol' that motor, and with a starting-rheostat 18. W' hen the line voltage i'alls, the core 10 will drop to open the switch 1. ln the event ol an overload the core 7 will be elevated, tripping both ol the switches.

In Fig. 4 is shown a double-pole circuitbreaker operating with minimum voltage and with maximum current. ln this instance the coil 1.1, which is ol high resistance, is connected directly across the line through the switch 1. The overload-coil 8 is in series with the switches l and 14 and. with a series motor 1S), provided also withastarting-rheostat 1S. \'\"hcn the electromotive l'orce is on the line, the core 10 is raised and the switch 1. closed, so that the shunt-coil 11 will be connected directly across the line and excited and the core held in its elevated position. The switch 1.4 is now closed, completing the circuit through the overload-coil 8, motor 10, and starting-rheostat 18. When the voltage drops below the predetermined limit, the core 10 will descend by its weight, releasing the switch 1, which opens the circuit to the motor. ln the event ol an overload the core 7 will be elevated' to trip the latches of both the switches. The startingrheostat with this iorm of device is ol" a wellknown type, having no open circuit, but provided with a spring constantly tending to bring its operating-lever to a position to include the entire resistance in the circuit. W hen the operating-lever is in its full-speed position-Ji. e., with the resistance cut outit is held in that position by contacts 20 or other equivalent device, as is common. The arrangement shown in Fig. 4 is especially -usel'ul lor motors of very large size, (say.

three-hundred-horse power) especially when the voltage is about one hundred and twenty volts, as itis very diiicult to make a startingrheostat having in itself automatic features jfor such service on account of the necessary weight and friction oi the operating-lever, both of which factors -nteri'ere with the proper laction of the automatic features,

IOO

which would work successfully in connection with starters for small motors.

In Fig. the coil 11, which operates when a definite drop in voltage takes place, is connected across the line between the switches 1 and 14, as shown. instance operates when an increase in the electroiiiotive i'orce heyond the desired limit takes place and is also connected across the line and in series with said switches.; As shown, the device is illustrated as being used in connection with the charging of a storage hattery 21. vIn the event or a drop .in electrornotive iorce the coil- 11 will he weakened or denergized, permitting the core 1() to fall and open the switch 1, while in the eveiit'ot' an abnormal increase in the velectromotive force the coil 8 will, be sufficiently energized to elevate the core 7 with a gadu al acceleration to release switches 1 and 14.

In Fig. 6 I illustrate a double-pole circuitbreaker arranged to protect a translating device against an excessive increase of electromotive force and'current. With this modification the overload-coil 8 is in series with the switch 1, while the maximum-voltage coil 22 (which is used instead of' the coil 11) is connected across the line, so las to shunt the translating device 23. As in the previous forms of the invention, the core 7 is adapted to he elevated in the event of an overload to release theswitch l14. IVith the present modification the maximum-voltage*coil 22 is arranged to elevatea core 24, arranged like the core 7 and which eilects the release of the switch 1. It will lre observed that in the event of an overload the coil 8 will operate the switch 14, and in the event of an abnornial increase of electromotive jforce the coil 22 will operate the switch 1. In some instances it is desirahle to have a circuithreaker not only automatic as to overload, as explained, but also having means whereby it may be opened from a distance by closing a controlling-circuit. rIhus, referring to Fig.' 12, an auxiliary circuit may extend to a distant point and he provided with an operating-switch 26 therein, so that by operating the switch 26 the coil 22 may he energized. It will of course he understood that when the circuit 25 is not used the coil 22 will be so proportioned to its core 24' that the latter will be elevated when an abnormal increase of electromotive force occurs on the line. When, however,` the auxiliary circuit 25 is used Jfor operating the` circuit-breaker from a distance, the circuit of coil 22 will be normally open and the coil will be so proportioned with respect to its core thatthe normal electrornotive force of the line Will he sufficient to effect the elevation of thecore 24 upon the closing of the circuit through the coil by switch 26.

In Fig. 7 I illustrate another complishing the same result.

way of ac- With this The coil 8 in the present `core 7.

modification I mount the coil 22 below the core 7 and arrange the core 24 to engage the lower end ot' the core 7 when the coil 22 is energized, the core 24 being adapted to slide up onvthe guide, which is shown extending to It will he seen that in the event of an overload the coil 8 will elevate its core 7 to release the switclr14 and also the switch 1, if desired. If now it is desired to open the circuit from a distance, the switch 26 will he operated, closing the circuit through the coil 22, elevating the core 24. with a gradual acce eration until it strikes the core 7, which will itself he then elevated to release the switch 14 or switches 1 and 14. v

In Fig. 8 I illustrate a reverse-current circuit-breaker which opens both switches automatically if the current charging a storage hattery, as shown, should reverse due to the electrornotive force olthesource falling below that of the battery. The coil 8, which in the present instance is allected by the current, is connected in series with the storage hattery heing charged. Its core 7 when elevated trips both the switches 1 and 14. Cooperating with the core 7 is a coil 27, which is shuiited across the line and which is provided in series with it with an adjusting-rheostat 25, by which its magnetic effect may be adjusted. Then the current flows to the hattery in the normal direction, the iiiagnetizing eil'ects of the two coils are counter to each other, so that the core 7 will not he elevated. It', however, the current in the local batterycircuit reverses -in sense, the eilect of the coil 8 will he to supplement the coil 27, elevating the plunger' and opening the circuit-breaker. The rheostat 2S enables one toadjust the device so that a predetermined current-'llow will cause the circuit to he opened. For example, wlien no current flows in coil S the coil 27 may have suilicient current to cause the circuit-breaker to he opened, or the adjustment may he such that a reversed current of predetermined strength is required before the circuit will he opened.

' In the forni or' the invention justdescribed and in all others in which the core is raised by magnetism against gravity the initial position of the core relative to .its coil is adjustable hy means ol adjusting-screw-St, so that the amount of magnetic effect necessary to start the core can be varied as desired, anda scale will also be used indicating to the operator the desired initial. adjustment of thel core in order that a definite magnetic effect, as determined by aniperes or volts, may be obtained to eiiiect the elevation of the core. Also in those constructions where a raised core is allowedto 'fall and trip the mechanical restraining means upon the occurrence 0il certain conditionsit will he understood that the adjustment'of a part, suoli as screw 12, Fig. 1, will vary the restraining force required to keep the core or plunger raised, and

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vthrough the battery the coil 8 will oppose the coil 27, permitting the core 7 to drop and opening the circuit-breakers. It will be understood that where I have shown two coils cooperating to actin a certain way, as in Figs 7 to 9, they may be variously arranged, and

the two cores may ordinarily be joined mechanically or may be united into a single core. Also the two coils may sometimes be arranged one above the other, or in many iiistances one may be superimposed upon the other, and in practice the latter construction is preferable. The displacement of the coils with reference to each other, as shown in the drlwings, adds to the clearness, however.

ln lig. l0 I illustrate a iin-voltage and overload circuit-lncaler employed in connection with a shunt-iiiotor. XViththis modi'iication the cores 7 and 10 are mechanically connected together. The lio-voltage coil 1l is connected directly across the line, so that normally both of the cores will be elevated and the circuit-breakers l and la closed. A normal current lor operating the motor energiZes the coil 8 and tends to pull downwardly on the core 7; but this eiiect is not su'thcient to oppese the attraction of the coil 11. l'n the event of an overload, however, the coilS will be sulliciently energized toI overcome the attraction of the coil ll, starting the cores downwardly, which movement Igradually accelerates to trip the latches of one or both of the switches. In the event oi. a drop of electromotive farce below the normal limit the coil ll will be sufficiently denergized to release the core i0, and both of the cores will then descend, so as to open one or both of the switches. lNith this inodi'lication, therefore, the same movement of the cores will be eifected by a drop in electroinotive force and by an increase of current. Of course in many instances the two cores 7 and i() may' be one elongated core, or core 7 may be ad- Aadjustablev along the rod shown, passing through its center to vary the relative eilects of the two coils. i

Referring to Fig. ll, 'itshow a somewhat similar arrangement to that shown in F ig. 6, the device being used in connection with the charging oi a storage battery, which is con- .nected in series with the magnet 29 oi a polarized relay.

The armature 3() of the lrelay is provided with a' magnetizingcoil 31,- connec-ted across/the battery, for magnetizing it in a definite sense, as shown. The armature 3() of the polarized relay is in circuit with the coil 22'; `but that circuit is normally broken at the contact 32, which is controlled by said armature. Normally the armature Si) will be in contact with a bach-stop 33, so that the coil 22 will be denergizcd. ln the event of a reversal of current, however, through the battery the magnetism of the magnet 29 will be reversed. in sense, moving the armature 30 in the other direction and closing the contact 32 to energize the coil 22, elevate the core 24, and open the switch. .ln

the event of overload the overload-coil 8 nld vates its core 7 as usual.

It will be understood that the constructions indicated in Figs. 8, 9, and 1l are applie cable to any form of apparatus where one source is in circuit with another-such, for example, where two dynamos are in parallel and where an abnormal reversed current may iiow between the two sources of electro# motive force.

It is very advantageous to provide two in dependeiitly-operative switches in the circuit as described, and shown in the various iigures, not only as regards greater reliability and eliiciency ol the apparatus, but also on account of the advantage secured which overcomes the danger oi' the operator keeping the circuit closed when an overload, short circuit, or other objectionable condition exists. For example, when the operator closes one switch and then the other if any abiiormal electrical condition exists the first will be opened automatically, even though the second is held closed by the operator, and the possibility of maintaining theciicuit closed is thus avoided.

Although the drawin gs are largely diagram matic, the general construction indicated in each Acase will be understood and may be similar in general vto that shown in Figs. l to 8.

Having now described my invention, what l claim as new, and desire to secure by Let' abnormal electrical condition orn said circuit said device falls and performs its function, and also comprising a second switch, a magnet, a magnetic mass movable against gravityl under the influence of said magnet when I-,its magnetic iniuen'ce exceeds a predetermined maximuin-due to a certain other abnormal clectrieal condition of said circuit,

and means for causing the movement of both .of said switches when said :magnetic mass is thus moved against the action of gravity.-

2. The combination' with a circuit, of a controller therefor, Isaid controller comprising a switch-arm, a magnet connected with said circuit Vand having-a co erating iron part normally up and which lia ls and causes namesaa movement of the switch-arm when rthe energy in said circuit 'falls below1 a predetermined limit, and also comprising a second switch, and second magnet having a cooper'- ating iron part normally down and which rises and causes movement of both of said switches when the energy in said circuit exceeds a predetermined limit.

3. The combination with an electric motor having its armature and field windingin shunt relation, of a circuit-controller' com prising a switch, a magnet in series with the field-winding and having a vertically-moving cooperating part 'which is normally sustained by magnetic action against gravity and which 'when no voltage occurs on the circuit falls and causes said switchto affect the armature-circuit, and also comprising a second switch, and a second magnet carrying the armature-current and having a vertically-moving cooperating part which Qis raised against gravity when the current through the motor-armature exceeds a predetermined amount and thereby causes both of said switches to affect the armature-cir cuit.

4. The combination with a circuit, of a cir cuit-controller, said controllery comprising two imlepcndently-movable switches connected in series in said circuit, two independ ent electroresponsive devices protectively related to rsaid switches and each having an automatically-movable part whose move.- ment is independent of the movement of the other part, one moving when the electrometive force upon the circuit becomes abnormal and the other moving when the current in the circuit becomes abnormal.

5. The combination with two indcpend.

ently-movable switches, of two independent electroresponsive devices and a device cooperating with each of said electroresponsive devices, one of which falls by gravity when the elcctromotivc force becomes too low and thereby causes the movement of one of said switches to affect the circuit, and the other .being raised against gravity when the current exceeds a predetermined amount and thereby causes the movement of one or both of said switches to affect the circuit.

6. The combination with two independently-movable switches, of two magnets, one having a cooperating'part normally held by magnetism against gravity and whichupon an abnormal electrical condition of the circuit allows the cooperating part to fall under the action of gravity and thereby cause the iiiovement of oneof said switches to affect the circuit, and a second magnet having the cooperating part normally down and which under a different abnormal electrical condition of the circuit is raised bymagnetism acting against gravity to cause the movement of one or both of said switches to affect the circuit.

1 7. The combination of two independentlymovable switches, an` electroresponsive device for automatically and simultaneously l effecting theopening of both of said switches when excessive current flows, and a secondv independent electroresponsive device for effecting independently of said first device the opening of only one of' said switches under an abnormal condition of electromotive force upon the circuit.

S. The combination of two independentlymovable switches, independent latches for holding said switches closed against means tending to open them, an electroresponsive device for automatically and simultaneously effecting the tripping of both o f said latches when excessive current flows, and a second independeiit lectroresponsive device for effecting independently of said first device the tripping of one of said latches under an abnormal condition of the electromotive force upon the circuit.

9. The combination of two independently-l `movable switches;` independent latches for holding said Aswitches closed against means tending to open them, .an electromagnet having a movable magnetic mass responding to excessive flow of current and arranged to move upward to trip both of said latches, and a second independent magnet having a movable magnetic mass responding to an abnormal condition oi the electromotive force upon the circuit and arranged to fall to trip only one of said latches.

`10. The combination of a plurality of electric switches adapted to be moved manually and independently into normal position, a controlling device for automatically controlling the movement of all of said switches upon the occurrence of a certain abnormal electrical condition, and a second controlling device for automatically controlling independently of said first device the movement of less than all of said switches upon the occurrence of a different abnormal electrical condition.

11.. The combination of a plurality of elec- IOO IIC

tric switches adapted to be moved manually and independently into normal position, a controlling device for, automatically controlling the movement of said switches upon the occurrence of overload-current and a second controlling device for automatically controlling independently of said first device the movement of less than' all of' said switches upon the occurrence of a different abnormal electrical condition.

12. The combination of a circuit, two independently-movablc switches connected in series in said circuit, a device having a movl 25 able mass which'under certain electrical conditions\\e the circuit moves automatically to effectv the opening of both of said switches, and a second indepeudently-acting device having a movable mass which under different 130 electrical conditions of the circuit movesautomatically to ellect the openingof at least one of said-switches, the direction of motion of Said two masses referred to being different.

18. The combination of a circuit, a switch connected in series in said circuit, a latch located below the switch-contacts for holding the movable part of said switch in closed po.

sition, said latch having two extensions, an electromagnetic device located on one side of ySaid contacts and having a movable art eX- tending below its winding, means be ow said winding and'controlled by said movable part for affecting said latch by acting upon one of said extensions, an electromagnetic device located at the opposite side of said contacts and having a movable part extending below its winding, means below said latter u inding and controlled by said latter movable part for affecting said latch by acting upon the other of said extensions, one of said devices acting upon the occurrence of one electrical condition of the circuit and the other of said devices acting upon the occurrence of a dil"- ferent electrical condition of the circuit.

14. The combination of a circuit, two independently-movable switches in series in 'said circuit, a latch located below the contacts of each of said switches for holding the movable part of each of said switches in closed position, an electromagnetic winding having a movable part, means below said winding and controlled by said movable part for tripping both of said latches upon the occurrence ot one electrical condition of the circuit, and additional electromagnetic means having a movable part for causing at least one of said latches to be tripped upon the occurrence of a ditlerent electrical condition, said additional means comprising a winding located above the part atlected by th'e movement of its movable tripping part.

l5. The combination of a constant electromotive-force-suppl circuit, an electric motor of the shunt-field type, controlling means therefor comprising two independently manually closablc switches connected in series with the motor-armature across said circuit, independent mechanical restraining means for each of said switches, independent means for each of said switches tending to open each switch separately, two electromagnetic responsive releasing means, each of said releasing means being independent of the other and each having a movable part which acts automatically and independently of the other part and delivers a blow to all'ect said restraining means, one ol' said releasing means being responsive to a predetermined overloadfcurrent for protecting said motor from SAL-5,655

excessive current and acting to cause the opening of both ol' sind switches, and the yother ol said releasing means being responvswitches upon overload if the other be held closed by the operator, said mean3comprising a movable part which when moved automatically delivers a blow to ell'cct the said opening of said switches, and an independent electroresponsive means for automatically ellecting the opening of at least one ot' said switches, said second means also comprising a movable part which when moved automat ically delivers a blow independently ol' the movement of said lirst-named part to ellect the opening of at least one ol said switches.

17. The combination of a motor ot' the shunt-field type adapted or use upon a constant electromotive-force circuit, controlling means therefor comprising two independently-movable switches in series with each other and with the motor-armature and adapted to be closed successively, independent mechanical restraining means for each ol' said switches, an independent spring for each of said switches each tending to open the switch which it controls, two electromagnetic responsive releasing means, each of said releasing means being independent of the other and each actin@ independently of the other for automatica ly and separately atl'ecting said restraining means, one of said releasing means being automatically resp(` sive to predetermined decrease ol' current in its winding and the other being automatically responsive to predetermined increase of current in its` winding, said switches and releasing means which responds to increase of current being protectively related so that one ol'- said switches will always be opened il' overload occurs when the last switch is closed for completing the circuit, and the said two respon- `sive means having dill'erent resultant etl'ects y 'upon said switches whereby a visual indication is obtained showing which of said re leasing means has acted.

This specification signed and witnessed this 2d day of March, 1901. i

H. WARD LEONARD.

Witnesses:

FRANK L.'DYER, JN0. R. TAYLOR. 

